Negative electrode and secondary battery

Abstract

A negative electrode and a secondary battery capable of improving cycle characteristics are provided. The negative electrode includes a negative electrode current collector, a negative electrode active material layer, a first layer provided between the negative electrode current collector and the negative electrode active material layer, and a second layer provided on the negative electrode active material layer. The negative electrode current collector contains at least one or more of copper, nickel, and iron, the negative electrode active material layer contains silicon, the first layer contains silicon, a metal element constituting the negative electrode current collector, and at least one or more of titanium, nickel, zinc, silver, iron, boron, indium, and germanium, and the second layer contains silicon and at least one or more of titanium, nickel, zinc, silver, iron, boron, indium, and germanium.

1 . A negative electrode comprising:
 a negative electrode current collector;   a negative electrode active material layer;   a first layer provided between the negative electrode current collector and the negative electrode active material layer; and   a second layer provided on the negative electrode active material layer,   wherein the negative electrode current collector contains at least one or more of copper, nickel, and iron, the negative electrode active material layer contains silicon,   the first layer contains silicon, a metal element constituting the negative electrode current collector, and at least one or more of titanium, nickel, zinc, silver, iron, boron, indium, and germanium, and   the second layer contains silicon and at least one or more of titanium, nickel, zinc, silver, iron, boron, indium, and germanium.   
     
     
         2 . The negative electrode according to  claim 1 , wherein an element constituting the first layer excluding silicon and a metal constituting the negative electrode current collector are same as an element constituting the second layer excluding silicon. 
     
     
         3 . The negative electrode according to  claim 2 , wherein
 the element constituting the first layer excluding silicon and the metal constituting the negative electrode current collector is titanium, and   the element constituting the second layer excluding silicon is titanium.   
     
     
         4 . The negative electrode according to  claim 1 , wherein
 a concentration of silicon contained on a negative electrode active material layer side of the first layer is higher than a concentration of silicon contained on a negative electrode current collector side of the first layer,   a concentration of the metal constituting the negative electrode current collector contained on the negative electrode current collector side of the first layer is higher than a concentration of the metal constituting the negative electrode current collector contained on the negative electrode active material layer side of the first layer, and   the second layer contains silicon throughout a thickness direction.   
     
     
         5 . A secondary battery comprising: the negative electrode according to  claim 1 ; a positive electrode; and an electrolyte.